CONSTANS delays Arabidopsis flowering under short days
CONSTANS delays Arabidopsis flowering under short days
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DOI：
10.1111/tpj.14171
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发表时间：
2019-03-01
期刊：
影响因子：
7.2
通讯作者：
Casal, Jorge J.
中科院分区：
文献类型：
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作者：
Luccioni, Laura;Krzymuski, Martin;Casal, Jorge J.
与短日照(SD)相比，长日照(LD)通过激活光周期途径促进拟南芥的开花。在这里，我们发现在极低浓度(3h)或黑暗(蔗糖)下的生长也在生物尺度上促进了开花，这表明与极低浓度相比，低浓度(SD)对开花有明显的抑制作用。Constans(CO)在SD条件下抑制开花，而在SD条件下CO的早期开花需要开花基因T(FT)。在SD处理下，FT在叶片中的表达水平处于基础水平，而在CO处理中，这些表达水平并未增强。这表明CO在A.thaliana中的作用并不是其同系物在水稻中作用的镜像。在顶端，CO促进了顶端花1号(TFL1)的表达，此时FT表达对开花起重要作用。在SD条件下，tfl1突变对co为上位性突变，而ft为tfl1上位性突变。这些观察结果与长期存在但尚未得到证实的模型是一致的，即CO可以通过影响TFl1的表达来抑制FT诱导的开花。
Long days (LD) promote flowering of Arabidopsis thaliana compared with short days (SD) by activating the photoperiodic pathway. Here we show that growth under very-SD (3 h) or darkness (on sucrose) also accelerates flowering on a biological scale, indicating that SD actively repress flowering compared with very-SD. CONSTANS (CO) repressed flowering under SD, and the early flowering of co under SD required FLOWERING LOCUS T (FT). FT was expressed at a basal level in the leaves under SD, but these levels were not enhanced in co. This indicates that the action of CO in A. thaliana is not the mirror image of the action of its homologue in rice. In the apex, CO enhanced the expression of TERMINAL FLOWER 1 (TFL1) around the time when FT expression is important to promote flowering. Under SD, the tfl1 mutation was epistatic to co and in turn ft was epistatic to tfl1. These observations are consistent with the long-standing but not demonstrated model where CO can inhibit FT induction of flowering by affecting TFL1 expression.